our journey is not complete until our gay brothers and sisters are treated like anyone else under the law. for, if we are truly created equal, then surely the love we commit to one another, must be equal, as well. >> reporter: but obama, four years ago, talked about the audacity of hope, now gives a nod to reality. reminding his most fervent supporters that progress requires compromise. >> we must act knowing that our work will be imperfect. we must act knowing that today's victories will be only partial. >> reporter: before he headed back into the capitol, president obama stopped to look in awe at that amazing view of the national mall. >> take a look one more time. i'm not going to see this again. >> reporter: afterwards, the obama family took in the parade in a decidedly less formal way. dancing, snapping photos. and even chewing gum. and while all those hundreds of thousands of people who filled the mall have now helped president obama win his last campaign, the last campaign he says he will ever run, he's still counting on their support building a grassroots organization to get thing